the often unavoidable issues raised by excess derivatisation reagent and side reactions. As such, derivatisation methods tend to be exploited in groups with a chemistry background; however, the availability of reagents in kit format should facilitate the use of these methods by MS groups in general. Chapter 7. Unsaturated Lipid Analysis via Coupling the Paternò - Büchi Reaction with ESI-MS/MS. Xiaoxiao Ma and Yu Xia. Pages 148 - 174 Unsaturated lipids, which are characterized by the presence of one or multiple carbon - carbon double bonds (C=Cs) in fatty acyl/alkyl chains, constitute a significant proportion of all lipid species. Structural characterization and quantitation of unsaturated lipids, especially the location of unsaturation, is becoming increasingly important in lipid analysis. In this chapter, we introduce the combination of the Paternò - Büchi (PB) reaction, a fast (10 - 30 s) and highly specific C=C derivatization reaction with subsequent ESI-MS/MS for unsaturated lipid analysis. Upon low energy CID, the PB reaction products produce fragment ions specific to the original location of a C=C, allowing both structural identification and quantitation of unsaturated lipids. Acetone has been employed as the PB reagent throughout these studies, which shows the advantages of good compatibility with ESI as a co-solvent and little interference for MS analysis. Starting with a brief background introduction of the chemistry of the PB reaction, we will discuss the experimental setup for implementing the PB reaction online with ESI-MS, the typical reaction phenomena, MS/MS methods for structural identification and quantitation based on CID of the PB products, using unsaturated standard lipids of fatty acids (FAs), glycerophospholipids (GPs), and cholesteryl esters (CEs) as examples. Applications of PB-MS/MS in shotgun lipid analysis are demonstrated with human plasma, cells, plants and animal tissue samples. The potential of PB-MS/MS in biomedical research is demonstrated by detecting composition changes of lipid C=C location isomers from human prostate cancer cells and mouse breast cancer tissues. Chapter 8. Conventional and Current Methods for the Analysis of Hydroxy Fatty Acids. Nuanyi Liang and Jonathan M. Curtis. Pages 175 - 222 Hydroxy fatty acids (HFAs) are important constituents of cellular structures. They are involved in processes such as the moderation of membrane fluidity, single- or multi-cellular signaling processes and the self-defense of organisms. These bioactivities are often distinct from those of their non-hydroxy metabolic precursors or analogs. Furthermore, their presence is an indicator of the extent of lipid oxidation, metabolic status, disease development and species identification. Due to their low abundance (with a few notable exceptions), and their complexity and susceptibility to isomerize and degrade, HFA profiles can be difficult to determine and quantify. However, such information is critically important to understanding the biological processes in which they participate. This chapter is a summary of the progress that has been made to identify and quantify HFAs. It begins with a description of the biological significance of HFAs, which has stimulated interest in developing novel approaches to the qualitative and quantitative measurement of HFA species and profiles. Chapter 9. Mass Spectrometry of Lipid Vitamins. Jonas Abdel-Khalik. Pages 223 - 262 The deficiency of lipid vitamins is a worldwide issue. Deficiency in these vitamins has been associated with multiple diseases. Thus, there is an increasing interest in the assessment of the status of vitamins A, D, E and K. Usually, serum or plasma levels of one or more vitamin species or metabolites thereof are determined when assessing vitamin status. Lipid vitamins have historically been determined by either immunoassays, or ultraviolet, fluorescence and electrochemical detection. Mass spectrometry combines sensitivity, specificity with structural elucidation and is therefore gaining popularity and becoming the gold standard for analysis of vitamin lipids. This chapter reviews the analysis of lipid vitamins in serum or plasma by liquid chromatography or gas chromatography coupled to mass spectrometry. Sample preparation, the chromatographic setup, ionisation, derivatisation techniques, and common fragments formed during tandem mass spectrometry, are reviewed for each lipid vitamin. Chapter 10. New Scans and Resources in Lipidomics. W. J. Griffiths and Y. Wang. Pages 263 - 282. In the 1970s and 1980s, lipidomics existed but under the guise of 'metabolite profiling', largely performed on gas chromatography - mass spectrometry (GC-MS) instruments or using fast atom bombardment (FAB) ionisation on high-resolution magnetic sector MS instruments. Today, lipidomics has become a field of study in its own right with electrospray as the dominating ionisation mode, i.e. ESI-MS, often linked with online